import math
def getNum():
    nums=[]
    inumstr = input("请输入数字")
    while inumstr!="":
        nums.append(eval(inumstr))
        inumstr = input("请输入数字")
    return nums
def mean(numbers):
    s=0.0
    for num in numbers:
        s = s+num
    return s/len(numbers)
def dev(numbers,mean):
    sdev = 0.00
    for num in numbers:
        sdev = sdev+(num - mean)**2
    return math.sqrt(sdev/(len(numbers)-1))


n = getNum()
m= mean(n)
print("pjs:{},fc:{:.2}".format(m,dev(n,m)))
